Method for preparing polymers containing cyclopentanone structures

ABSTRACT

A method to electrolytically polymerize aromatic hydrocarbons and oxidize cyclopentane structures within the hydrocarbons into cyclopentanone structures is disclosed including a method to electrolyze fluorene in the presence of an ester to produce poly(9-fluorenone). A method to electrolytically oxidize polymers having cyclopentane structures to polymers having cyclopentanone structures is also disclosed including a method to electrolyze poly(fluorene) to produce poly(9-fluorenone). In addition, a method to chemically oxidize polymers containing cyclopentane structures into polymers containing cyclopentanone structures is disclosed, including a method to oxidize poly(fluorene), with a chemically prepared oxidizing agent, to produce poly(9-fluroenone).

FIELD OF THE INVENTION

[0001] This application relates generally to a method for the productionof polymers having at least one unit containing at least onecyclopentanone structure condensed with at least two aromatic rings byelectrolyzing aromatic compounds that have at least one cyclopentanestructure condensed with at least two aromatic rings, or by electrolyticor chemical oxidation of polymers that have at least one unit containingat least one cyclopentane structure condensed with at least two aromaticrings, and more particularly to a method for the electrolysis offluorene or its derivatives, and for the oxidation of poly(fluorene) orits derivatives, to poly(9-fluorenone) or its derivatives.

BACKGROUND OF THE INVENTION

[0002] Isomers of poly(9-fluorenone), such as 2,7-poly(9-fluorenone),may be employed in bi/multilayer light-emitting diodes (LED) operatedwith Mg as a cathode. Uckert, F. et. al., Advanced Materials, Vol. 12,No. 12, p.p. 905-908 (2000). However, poly(9-fluorenone) has provendifficult to prepare, in particular, 9-fluorenone does not appear tohave been electrolytically polymerized to date. Zecchin, S., et al.,Journal of Electroanalytical Chemistry, Vol. 215, p.p. 377-383 (1986).

[0003] Currently, there are two main methods for preparingpoly(9-fluorenone), and in particular, 2,7-poly(9-fluorenone). Onemethod uses five separate and distinct steps, starting from malonicester. The malonic ester is treated to produce 2,2-dioctylmalonic esterand in a separate step subsequently reduced with lithium aluminumhydride to provide a diol compound, 2,2-dioctyl-1,3-propanediol. Thediol compound is then combined with 2,7-dibromo(9-fluorenone) which mustbe produced from fluorene in two separate steps. The result of thecombination of the diol with the 2,7-dibromo(9-fluorenone), underappropriate conditions, is2,7-dibromo-spiro(4′,4′-dioctyl-2′,6′-dioxocyclohexane-1′,9-fluorene).The2,7-dibromo-spiro(4′,4′-dioctyl-2′,6′-dioxocyclohexane-1′,9-fluorene) ispolymerized with a nickel catalyst to provide2,7-poly(spiro(4′,4′-dioctyl-2′,6′-dioxocyclohexane-1′,9-fluorene)). The2,7-poly(spiro(4′,4′-dioctyl-2′,6′-dioxocyclohexane-1′,9-fluorene)) istreated with dichloroacetic acid to give the final product,2,7-poly(9-fluorenone). Uckert, F., et al., Macromolecules, Vol. 32, No.14, p.p. 4519-4524 (1999).

[0004] In a second method for preparing poly(9-fluorenone),2,7-dibromo-9-fluorenone, obtained by a two-step process from fluorene,is converted to Ni(PPh₃)₂(2-bromo-7-fluorenonyl)Br, which is thenreduced electrochemically to give 2,7-poly(9-fluorenone). Zecchin, S.,et al., Journal of Electroanalytical Chemistry, Vol. 215, p.p. 377-383(1986).

[0005] Each method requires several separate steps and both have provento be complicated and troublesome, involving the use of many potentiallyhazardous chemicals. Further, the methods have generally resulted in lowpolymer yields and high levels of impurities or byproducts.

[0006] Recently, Zecchin et al. alleged that 2,7-poly(9-fluorenone)films could be obtained from 2,7-poly(fluorene) films via oxidation withelectrochemically generated superoxide. Zecchin, S., et al., Journal ofElectroanalytical Chemistry, Vol. 215, p.p. 377-383 (1986). The report,however, provided no analysis of the film material to support thefindings and Uckert et al. (Macromolecules, Vol. 32, No. 14, p.p.4519-4524 (1999)) has disputed that the polymer obtained was in fact2,7-poly(9-fluorenone), based on inconsistencies within Uckert's data.Therefore, it is unclear if the Zecchin described superoxide method hasutility for preparing poly(9-fluorenone).

[0007] As such, the methods for preparing poly(9-fluorenone) have provento be of limited value. Accordingly there is a need for a simple andcost-effective method for producing poly(9-fluorenone) as well as otherpolymers having cyclopentanone structures. Against this backdrop thepresent invention has been developed.

SUMMARY OF THE INVENTION

[0008] Embodiments of the present invention include the electrolyticproduction of polymers wherein each polymer contains at least one unithaving at least one cyclopentanone structure condensed with at least twoaromatic rings. The method includes the electrolysis of a startingmaterial in the presence of an ester. The particular polymer produced bythe methods of the present invention depends on the starting material.The starting materials are aromatic compounds that have at least onecyclopentane structure condensed with at least two aromatic rings. Suchmaterials are polymerized and the cyclopentane structure is oxidizedinto a cyclopentanone structure by methods of the present invention.

[0009] One example of an embodiment of the present invention is a methodfor producing poly(9-fluorenone) by electrolysis of fluorene in thepresence of an ester. Embodiments of the method include passing anelectric current through an electrolytic mixture comprising fluorene, anester, and an electrolyte. Note that, depending on the ester,electrolyte, and reaction conditions, an additional solvent may beincluded in the electrolytic mixture to dissolve the ester, fluorene orelectrolyte, or to increase the yield of the poly(9-fluorenone).

[0010] Polymers containing at least one unit that has at least onecyclopentane structure condensed with at least two aromatic rings mayalso be used as a starting material. In embodiments using polymers asstarting materials, the cyclopentane structures within the polymer areoxidized to the cyclopentanone structures. One example of this type ofembodiment is a method for producing poly(9-fluorenone) frompoly(fluorene) via electrolytic oxidation.

[0011] Additional embodiments of the present invention include a methodof producing polymers containing at least one unit that includes atleast one cyclopentanone structure condensed with at least two aromaticrings via chemical oxidation of polymer starting materials. One exampleof the chemical oxidation embodiments of the present invention is amethod for producing poly(9-fluorenone) from poly(fluorene) via chemicaloxidation with a chemically prepared oxidizing agent.

[0012] These and various other features as well as advantages whichcharacterize the present invention will be apparent from a reading ofthe following detailed description and a review of the associateddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 shows examples of polymers containing at least one unithaving at least one cyclopentanone structure created by embodiments ofthe present invention.

[0014]FIG. 2 shows one possible reaction scheme for the electrolysis offluorene to poly(9-fluorenone) in the presence of an ester.

[0015]FIG. 3 shows a schematic representation of an electrolytic cellsuitable for embodiments of the present invention.

[0016]FIG. 4 illustrates the chemical structure of a portion of a2,7-isomer of poly(9-fluorenone) produced by embodiments of the presentinvention.

[0017]FIG. 5 illustrates the chemical structure of a portion of a2,7-isomer of a polymer having 9-fluorenone units and fluorene unitsproduced by an embodiment of the present invention.

[0018]FIG. 6 shows the chemical structure of a portion of a 2,7-isomerof poly(fluorene).

[0019]FIG. 7 shows one possible reaction scheme for the electrolyticoxidation of poly(fluorene) to produce poly(9-fluorenone).

DETAILED DESCRIPTION

[0020] The following definitions are provided to facilitateunderstanding of certain terms used frequently herein and are not meantto limit the scope of the present disclosure.

Definitions

[0021] “Alkoxy group of C₁ to C₁₀” when used in the context of thepresent invention are exemplified by methoxy, ethoxy, propoxy,isopropoxy, butoxy, isobutoxy, tert-butoxy, pentoxy, hexyloxy,heptyloxy, octyloxy, nonyloxy, and decyloxy

[0022] “Alkoxycarbonyl group of C₂ to C₁₀” when used in the context ofthe present invention are exemplified by methoxycarbonyl,ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentoxycarbonyl,hexyloxycarbonyl, heptyloxycarbonyl, octyloxycarbonyl, nonyloxycarbonyl,and decyloxycarbonyl.

[0023] “Alkyl group of C₁ to C₁₀” when used in the context of thepresent invention are exemplified by methyl, ethyl, propyl, isopropryl,butyl, isobutyl, tert-butyl, penty, hexyl, heptyl, octyl, nonyl, anddecyl.

[0024] “Aryl group of C₆ to C₁₀” when used in the context of the presentinvention are exemplified by phenyl, tolyl, xylyl, fluorophenyl,chlorophenyl, bromophenyl, iodophenyl, difluorophenyl, trifluorophenyl,pentafluorophenyl, (trifluoromethyl)phenyl, bis(trifluoromethyl)phenyl,cyanophenyl, and naphthyl.

[0025] “Aryloxy groups of C₆ to C₁₀” when used in the context of thepresent invention are exemplified by phenoxy, tolyloxy, and naphthoxy.

[0026] “Aryloxycarbonyl group of C₇ to C₁₁” when used in the context ofthe present invention are exemplified by phenoxycarbonyl,tolyloxycarbonyl, and naphthoxycarbonyl.

[0027] “Electrolytic mixture” refers to any liquid mixture that iscapable of conducting an electric current.

[0028] “Ester” refers to carbonic esters and lactones, as well as simpleesters, such as formates, acetates, propionates, and butyrates, and morecomplex esters, such as pentoates, decanoates, benzoates, toluates,icosanoates, and the like.

[0029] “Haloalkyl group of C₁ to C₁₀” when used in the context of thepresent invention are exemplified by fluoromethyl, chloromethyl,bromomethyl, iodomethyl, difluoromethyl, dichloromethyl,trifluoromethyl, trichloromethyl, trifluoroethyl, perfluoroethyl,trifluoropropyl, perfluoropropyl, perfluorobutyl, perfluoropentyl,perfluorohexyl, perfluoroheptyl, perfluorooctyl, perfluoronanyl, andperfluorodecyl.

[0030] “Halogen atom” or “halogen” when used in the context of thepresent invention is exemplified by fluorine, chlorine, bromine, andiodine atoms.

[0031] “Poly(9-fluorenone)” refers to any polymer that has at least one9-fluorenone unit and/or at least 1% W/W 9-fluorenone units, andpreferably a polymer having at least 10% W/W 9-fluorenone units, morepreferably a polymer having at least 50% W/W 9-fluorenone units, andmost preferably at least 80% W/W 9-fluorenone units. It should beunderstood that such polymers may contain one or more of the possibleisomers of 9-fluorenone units within the polymer structure, includingfor example, but not limited to, the 1,5-isomer, the 1,6-isomer, the1,7-isomer, the 1,8-isomer, the 2,5-isomer, the 2,6-isomer, the2,7-isomer, the 2,8-isomer, the 3,5-isomer, the 3,6-isomer, the3,7-isomer, the 3,8-isomer, the 4,5-isomer, 4,6-isomer, 4,7-isomer, andthe 4,8-isomer. Such polymers are preferably at least a total of 3 unitsof 9-fluorenone or of 9-fluorenone and other units in length and aremore preferably at least 7 units in length, more preferably 20 units inlength, more preferably 50 units in length, furthermore preferably atleast 165 units in length, and most preferably at least 200 units inlength.

[0032] “Poly(fluorene)” refer to any polymer having at least onefluorene unit and/or at least 1% W/W fluorene units, and preferably apolymer having at least 10% W/W fluorene units, more preferably apolymer having at least 50% W/W fluorene units, and most preferably atleast 80% W/W fluorene units. It should be understood that such polymersmay contain any and all possible isomers of fluorene units within thepolymer structure, including for example, but not limited to, the1,5-isomer, the 1,6-isomer, the 1,7-isomer, the 1,8-isomer, the2,5-isomer, the 2,6-isomer, the 2,7-isomer, the 2,8 isomer, the3,5-isomer, the 3,6-isomer, the 3,7-isomer, the 3,8-isomer, the4,5-isomer, 4,6-isomer, 4,7-isomer, and the 4,8-isomer.

[0033] “Unit” when used in the context of a polymer refers to any isomerof a monomer contained in the polymer, such that “a polymer having atleast one unit of fluorene” refers to any polymer that has at least onefluorene structure of any isomer within the polymer chain.

Electrolytic Production of Polymers Containing Cyclopentanone Structures

[0034] Embodiments of the present invention include the electrolyticproduction of polymers from a starting material in the presence of anester. Polymers that can be produced by methods of the present inventioninclude polymers containing at least one unit that has at least onecyclopentanone structure condensed with at least two aromatic rings. Apreferred example of the present invention is the electrolyticproduction of poly(9-fluorenone). Other preferred exemplary polymersthat can be produced by the methods of the present invention include,but are not limited to, poly(benzo[b]fluoren-11-one),poly(dibenzo[b,h]fluoren-12-one),poly(cyclopenta[def]phenanthren-4-one),poly(8H-cyclopenta[def]fluoren-4-one), andpoly(cyclopenta[def]fluorene-4,8-dione), andpoly(indeno[1,2-b]fluorene-6,12-dione), as shown in FIG. 1.

[0035] The starting materials for use in the present invention arearomatic compounds that have at least one cyclopentane structurecondensed with at least two aromatic rings. In addition, the startingmaterial can be polymers that have at least one unit containing at leastone cyclopentane structure condensed with at least two aromatic rings.

[0036] One preferred embodiment of the starting materials for use in themethods of the present invention has the general formula (I):

[0037] wherein any of the adjacent groups R¹ and R², R² and R³, R³ andR⁴, R⁵ and R⁶, R⁶ and R⁷, R⁷ and R⁸ may be bonded together by a group ofthe general formula —CR⁹═CR¹⁰—CR¹¹═CR¹²—, or be a group with the generalformula (II):

[0038] thus forming additional ring structures. Furthermore, theadjacent group R⁴ and R⁵ may be bonded together by a group with thegeneral formula —CR¹⁷═CR¹⁸— or —CH₂—. Simultaneously, at least two ofthe groups R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴R¹⁵, R¹⁶, R¹⁷ and R¹⁸ are hydrogen atoms. The remaining groups can beany combination of hydrogen atoms, halogen atoms, alkyl groups of C₁ toC₁₀, haloalkyl group of C₁ to C₁₀, aryl groups of C₆ to C₁₀, alkoxygroups of C₁ to C₁₀, aryloxy groups of C₆ to C₁₀, alkoxycarbonyl groupsof C₂ to C₁₀, and aryloxycarbonyl groups of C₇ to C₁₁.

[0039] A simple example of a starting material, wherein the groups R¹,R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸ are hydrogen, is fluorene. When fluoreneis used as a starting material, the method of the present inventionproduces poly(9-fluorenone), as described in greater detail below.

[0040] Another example of a starting material is 11H-Benzo[b]fluorene,as shown below:

[0041] which would produce polymers having recurring units ofbenzo[b]fluoren-11-one (see FIG. 1).

[0042] Another example of a starting material for use with the presentinvention is 4H-cyclopenta[def]phenanthrene, wherein the adjacent groupsR⁴ and R⁵ are bonded to —CR¹⁷═CR¹⁸— and where R¹⁷ and R¹⁸ are hydrogenand the remaining R groups are hydrogen:

[0043] When used as a starting material, 4H-cyclopenta[def]phenanthrenecan be used to produce polymers having units ofcyclopenta[def]phenanthrene-4-one (see FIG. 1).

[0044] Another example of a starting material for use with the presentinvention is 4,8-dihydro-cyclopenta[def]fluorene, wherein the adjacentgroups R⁴ and R⁵ are bonded to a methylene —CH₂— and the remaining Rgroups are hydrogen:

[0045] When used as a starting material,4,8-dihydro-cyclopenta[def]fluorene can be used to produce polymershaving units of 8H-cyclopenta[def]flouren-4-one and/orcyclopenta[def]fluorene-4,8-dione (see FIG. 1).

[0046] Another example of a starting material for use with the presentinvention is 6,12-dihydro-indeno[1,2-b]fluorene, wherein the adjacent R²and R³ are bounded to a group having the general formula:

[0047] (R² is bonded to the CH₂ carbon), where R¹³, R¹⁴, R¹⁵ and R¹⁶ arehydrogen and the remaining R groups are hydrogen:

[0048] When used as a starting material,6,12-dihydroindeno[1,2-b]fluorene can be used to produce polymers havingunits of 12H-indeno[1,2-b]fluoren-6-one and/orindeno[1,2-b]fluorene-6,12-dione (see FIG. 1).

[0049] Embodiments of the present invention include the electrolyticproduction of polymers from the starting materials described above inthe presence of an ester, and, alternatively, from polymers containingat least one unit of the starting materials described above in thepresence of an ester. For purposes of illustration, embodiments of thepresent invention are described with respect to the electrolyticproduction of poly(9-fluorenone) from fluorene and, alternatively, frompoly(fluorene). However, it should be clear to one of skill in the art,that the methods described below and throughout the specification areequally applicable to preparing polymers from any of the startingmaterials described above, or from any polymer that incorporates atleast one unit of the starting materials described above, all of whichare considered to be within the scope of the present invention.

[0050] Methods Utilizing Electrolysis of Fluorene in the Presence of anEster:

[0051] An embodiment of present invention is the electrolysis offluorene carried out in the presence of an ester, to formpoly(9-fluorenone). The electrolysis is achieved by flowing electriccurrent between electrodes immersed in an electrolytic mixturecomprising fluorene, an ester and an electrolyte. Note that, dependingon the ester and electrolyte used, an additional solvent may be requiredto dissolve the ester, electrolyte or fluorene, or used to increase theyield of the product, and may be included in the electrolytic mixture.

[0052] A possible mechanism for one preferred embodiment of anelectrolysis method in accordance with the present invention is shown inFIG. 2. In the first step of the reaction, fluorene, represented byformula III, is electrolyzed, which polymerizes the fluorene intopoly(fluorene), represented by formula IV. Note that the parentheticalrepresentation of the polymer bond in formula IV, consistent with thedefinition of poly(fluorene), is used to represent polymers having anypossible isomer units of fluorene within the polymer structure. Ingeneral, the poly(fluorene) is deposited on an electrode in theelectrolytic cell. Continued electrolysis of the poly(fluorene) stripstwo electrons and a proton at the 9 positions of the recurring units offluorene in the poly(fluorene), resulting in the ionic form ofpoly(fluorene), represented by formula V. The electrolysis is carriedout in the presence of an ester, represented by formula VI, whichreacts, via nucleophilic attack, with the ionic poly(fluorene) to createintermediary chemicals, represented by formula VII and VII′. Furtherreaction of the intermediary produces the poly(9-fluorenone),represented by formula VIII, and a byproduct, represented by formula IX.In general, the final polymer product is deposited as a film or solid onthe electrode. Note that the R and R′ groups on the ester may representany number of functional groups as is more fully described below in theenumeration of esters for use with the present invention.

[0053] The concentration of fluorene in the electrolysis shown in FIG. 2is preferably between 0.0001 and 10 mol/L, and more preferably 0.001 and1 mol/L. The concentration of electrolyte in the electrolysis ispreferably between 0.0001 and 10 mol/L, and more preferably 0.001 and 1mol/L, and the concentration of ester in a mixture is preferably atleast 10% (V/V) and more preferably at least 20% (V/V).

[0054] A schematic representation of one embodiment of an electrolyticcell for use with the present invention is illustrated in FIG. 3. Theelectrolytic cell includes a vessel 302, electrolytic mixture 304, twoelectrodes 306, and a power source 308. The two electrodes 306 contactthe electrolytic mixture 304 constrained within the vessel 302, and areconnected by a power source 308. The power source 308 supplies a voltagepotential between the electrodes 306, resulting in the current used inthe electrolysis of fluorene to poly(9-fluorenone). It will be clear toone skilled in the art that any electrolytic cell configuration may beadapted to perform the methods of the invention, including the use ofone or more additional reference electrodes (not shown) to assist in thecontrol of the electric potential. Also note that multiple workingelectrodes and/or electrolytic cells may be used in the context of thepresent invention to increase the yield of poly(9-fluorenone)production. Embodiments of the present invention may utilize any methodof electrolysis, including constant potential, constant current, and thepotential sweep methods. The electric current density can be suitablyselected for the adopted method or conditions, since it depends on thesolvents, electrolytes, reagent concentrations, electrode materials, andother factors. In general, the current density is preferably between0.001 and 100 mA/cm² and more preferably between 0.01 and 50 mA/cm² andfurther between 0.01 and 30 mA/cm². One or more reference electrodes maybe included for voltage control.

[0055] As briefly noted above, in general, the poly(9-fluorenone) isdeposited on an electrode 306 of the electrolytic cell 300. Typically,the deposition of the polymer begins immediately and, as the timeproceeds, the rate of the deposition decreases. Additional fluorene maybe added to the mixture during electrolysis. Depending on thecircumstances, electrolysis is conducted for as long as 48 hours, andmore preferably for 24 hours or less, before the polymer is harvested.The polymer can be easily removed from the electrode, e.g. by peeling,scraping, etc., and may be further dried by techniques well known in theart. In addition, if necessary, the polymer may be washed by an adequatesolvent before or after the polymer has been removed from the electrode.

[0056] The present invention includes utilizing the above method toproduce poly(9-fluorenone) (one isomer of which is shown in FIG. 4) aswell as polymers that have units of 9-fluorenone and fluorene (oneisomer of which is shown in FIG. 5, and see Example 3). Polymers havingunits of other compounds, in addition to 9-fluorenone, may also resultfrom the above-described method, and are envisioned to be within thescope of the present invention. The purity of the resultingpoly(9-fluorenone) is dependent on a number of factors, including theelectrolysis conditions and the nature and/or purity of the fluorene,esters, electrolytes, solvents, etc.

[0057] Methods Utilizing Electrolysis of Poly(Fluorene) in the Presenceof an Ester.

[0058] In another embodiment of the present invention, poly(fluorene),such as the 2,7-isomer of poly(fluorene) as shown in FIG. 6, may be usedas a starting material to prepare poly(9-fluorenone). In thisembodiment, one possible reaction to form poly(9-fluorenone) is shown inFIG. 7. The reaction follows the same steps as described above in FIG.2, except that the initial polymerization reaction is eliminated, andthe reaction starts from poly(fluorene). Poly(fluorene) may be preparedby the electrolysis of fluorene (as shown above in FIG. 2), or may beprepared by a number of well known methods for use in the presentinvention. Schiavon, G., and Zotti, G., Journal of ElectroanalyticalChemistry, Vol. 186, p.p. 191-199 (1985); Rault-Berthelot, J. andSimonet, J., New Journal of Chemistry, Vol. 10, No. 3-1986, p.p. 169-177(1985); Waltman, R. J., and Diaz, A. F., Journal of the ElectrochemicalSociety, Vol. 132, No. 3, p.p. 631-634 (1986).

[0059] Depending on the process used, the poly(fluorene) may include anumber of impurities. Use of such “non-pure” polymers of fluorene istypical and expected and within the scope the invention. It should notedthat this may result in correspondingly “non-pure” end products ofpoly(9-fluorenone)—i.e. the percent (W/W) of 9-fluorenone units will bedecreased relative to other polymer units. Poly(fluorene) having atleast one fluorene unit can be use and/or poly(fluorene) having at least1% W/W fluorene units can be used, but preferably a polymer having atleast 10% W/W fluorene units, more preferably a polymer having at least50% W/W fluorene units, and most preferably at least 80% W/W fluoreneunits can be used as the starting material in the methods of the presentinvention. The poly(9-fluorehone) produced by this method has at leastone fluorenone unit and/or has at least 1% W/W 9-fluorenone units andpreferably has at least 10% W/W 9-fluorenone units and more preferablyat least 50% W/W 9-fluorenone units and most preferably at least 80%9-fluorenone units.

[0060] Components for Electrolytic Production of Poly(9-Fluorenone):

[0061] Fluorene is common in nature and easily available. It is shown inFIG. 2 as formula III. References describing methods for the productionof poly(9-fluorene), as shown as formula IV in FIGS. 2 and 7, includethe following: Schiavon, G., and Zotti, G., Journal of ElectroanalyticalChemistry, Vol. 186, p.p. 191-199 (1985); Rault-Berthelot, J. andSimonet, J., New Journal of Chemistry, Vol. 10, No. 3-1986, p.p. 169-177(1985); Waltman, R. J., and Diaz, A. F., Journal of the ElectrochemicalSociety, Vol. 132, No. 3, p.p. 631-634 (1986).

[0062] Esters usable in embodiments of the present invention includesimple esters, carbonic esters, and lactones (a cyclic form of esters),in addition to other compounds that would be considered by a personskilled in the art to fall within the ester category. Preferable simpleesters include those with melting points less than 100° C. For example:methyl formate; ethyl formate; propyl formate; isopropyl formate; butylformate; isobutyl formate; t-butyl formate; phenyl formate; methylacetate; ethyl acetate; propyl acetate; isopropyl acetate; butylacetate; methyl propionate; ethyl propionate; propyl propionate; butylpropionate; methyl butyrate; and ethyl butyrate. Of these, the mostpreferable are methyl formate, ethyl formate, methyl acetate, ethylacetate, methyl propionate, ethyl propionate, and methyl butyrate.

[0063] Carbonic esters usable in embodiments of the present inventionare preferably those of which melting points are less than 100° C. Invarious embodiments, cyclic carbonic esters, such as ethylene carbonate,propylene carbonate, butylene carbonate, and trifluoropropylenecarbonate, and acyclic carbonic esters, such as dimethyl carbonate,diethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, ethyl methylcarbonate, dipropyl carbonate, di-isopropyl carbonate, methyl propylcarbonate, ethyl propyl carbonate, methyl propyl carbonate, dibutylcarbonate, di-isobutyl carbonate, methyl butyl carbonate, ethyl butylcarbonate, diphenyl carbonate, methyl phenyl carbonate, and mixtures ofthese are used. From a viewpoint of the efficiency of the electrolysisand cost, ethylene carbonate, propylene carbonate, butylenes carbonate,dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, andmixtures of these are more preferable.

[0064] Lactones usable in embodiments of the present invention arepreferably those that have melting points less than 100° C. For example:β-propiolactone; methyl-β-propiolactone; ethyl-β-propiolactone;propyl-β-propiolactone; isopropyl-β-propiolactone;phenyl-β-propiolactone; γ-butyrolactone; methyl-γ-butyrolactone;ethyl-γ-butyrolactone; δ-valerolactone; methyl-δ-valerolactone;ethyl-δ-valerolactone; ε-caprolactone; methyl-ε-caprolactone; andethyl-ε-caprolactone. Of these, β-propiolactone, γ-butyrolactone,δ-valerolactone, and ε-caprolactone are more preferable.

[0065] An ester that is normally solid at the temperature at which thereaction is conducted may be dissolved in another, normally liquid,ester or in a solvent as described below.

[0066] Solvents may be used to dissolve the ester, fluorene, and/or theelectrolyte, or to increase the yield of the product in embodiments ofthe present invention. Any solvent may be used that does not inhibit therole or effect of the ester or other components in the electrolysis. Invarious embodiments, the solvent may be: nitriles such as acetonitrile,propionitrile, and benzonitrile; nitro solvents such as nitromethane,nitroethane, and nitrobenzene; ethers such as tetrahydrofuran, diethylether, dimethoxyethane, and dioxane; halogenated alkanes such asdichloromethane, and dichloroethane; aromatic solvents such as benzene,toluene, chlorobenzene, and fluorobenzene; and mixtures of any of theabove. The total concentration of ester in the solvent may be anyconcentration in which the reaction can occur. Although it depends onthe nature of the solvent used and other factors, in a preferredembodiment the total concentration of ester in the electrolyte mixtureis more than 10% V/V, and in most preferred embodiment the totalconcentration of ester is more than 20% V/V.

[0067] Electrolytes used in electrolytic mixtures in embodiments of thepresent invention consist of a cation part and an anion part. Examplesof cation parts are: an alkali metal ion such as ions of lithium,sodium, or potassium; a quaternary ammonium ion; an onium ion; and aphosphonium ion. In preferred embodiments, an alkali metal ion and aquaternary ammonium ion are used. Examples of anion parts are:hexafluorophosphate ion (PF₆ ⁻), tetrafluoroborate ion (BF₄ ⁻),hexafluoroarsenate ion (AsF₆ ⁻), hexafluoroantimonate ion (SbF₆ ⁻),perchlorate ion (ClO₄ ⁻), triflate ion (CF₃SO₃ ⁻),bis(trifluoromethanesulfonyl)imide ion ((CF₃SO₂)₂N⁻), andtrifluorotris(pentafluoroethyl)phosphate anion (PF₃(C₂F₅)₃ ⁻). Inpreferred embodiments, BF₄ ⁻ and PF₆ ⁻ are used.

[0068] Embodiments of the present invention include using lithiumhexafluorophosphate (LiPF₆), sodium hexafluorophosphate (NaPF₆),potassium hexafluorophosphate (KPF₆), lithium tetrafluoroborate (LiBF₄),sodium tetrafluoroborate (NaBF₄), potassium tetrafluoroborate (KBF₄),tetramethylammonium tetrafluoroborate ((CH₃)₄NBF₄), tetraethylammoniumhexafluorophosphate ((C₂H₅)₄NPF₆), tetraethylammonium tetrafluoroborate((C₂H₅)₄NBF₄), tetrapropylammonium tetrafluoroborate ((C₃H₇)₄NBF₄),tetrabutylammonium tetrafluoroborate ((C₄H₉)₄NBF₄), tetrabutylammoniumhexafluorophosphate ((C₄H₉)₄NPF₆), tetrahexylammonium hexafluorophophate((C₆H₁₃)₄NPF₆), tetrahexylammonium tetrafluoroborate ((C₆H₁₃)₄NBF₄),benzyltrimethylammonium tetrafluoroborate, benzyltrimethylammoniumhexafluorophosphate, lithium perchlorate (LiClO₄), tetraethylammoniumperchlorate ((C₂H₅)₄NClO₄), tetrabutylammonium perchlorate((C₄H₉)₄NClO₄), lithium hexafluoroarsenate (LiAsF₆), lithiumhexafluoroantimonate (LiSbF₆), lithium triflate (CF₃SO₃Li),tetramethylammonium triflate (CF₃SO₃N(CH₃)₄), tetraethylammoniumtriflate (CF₃SO₃N(C₂H₅)₄), lithium bis(trifluoromethanesulfonyl)imide((CF₃SO₂)₂NLi), bis(pentafluoroethanesulfonyl)imide ((C₂F₅SO₂)₂NLi),lithium trifluorotris(pentafluoroethyl)phosphate (LiPF₃(C₂F₅)₃) andmixtures of any of these as electrolytes. Among them, LiPF₆, NaPF₆,KPF₆, LiBF₄, NaBF₄, KBF₄, (CH₃)₄NPF₆, (CH₃)₄NBF₄, (C₂H₅)₄NPF₆,(C₂H₅)₄NBF₄ are more preferable from a view point of cost, yield of thepolymer, and safety.

[0069] Electrode materials usable in electrolysis, in embodiments of thepresent invention, may be any of the conventional electrode materialsfor the electrolysis of organic compounds. Embodiments of the presentinvention include using, for example: metals such as platinum, gold,silver, nickel, iron, stainless steel, rhodium, iridium, aluminum,molybdenum, titanium, palladium, copper and the like; carbons such asgraphite, acetylene black, glassy carbon and the like; metal oxides suchas SnO₂, In₂O₃, TiO₂, PbO₂, IrO₂, RuO₂, and the like; and mixtures ofthese materials. The electrodes may also be coated with these materials.Among them, electrodes made of platinum, nickel, stainless steel,copper, carbons, and PbO₂ and electrodes coated with them such as, atitanium electrode coated with platinum or PbO₂ are preferable.

Chemical Oxidation to Produce Polymers Containing CyclopentanoneStructures

[0070] Additional embodiments of the present invention include theproduction of polymers containing at least one unit having at least onecyclopentanone structure condensed with at least two aromatic rings, viachemical oxidation of polymer starting materials having at least oneunit containing at least one cyclopentane structure condensed with atleast two aromatic rings. One preferred embodiment of the polymerstarting material for use in the present invention has the polymers thathave at least one unit of a general formula (X):

[0071] wherein any of the adjacent groups R¹ and R², R² and R³, R³ andR⁴, R⁵ and R⁶, R⁶ and R⁷, R⁷ and R⁸ may be bonded together by a group ofthe general formula —CR⁹═CR¹⁰—CR¹¹═CR¹²—, or having a general formula(XI):

[0072] thus forming additional ring structures. Furthermore, theadjacent group R⁴ and R⁵ may be bonded together by a group with thegeneral formula —CR¹⁷═CR¹⁸— or —CH₂—. Simultaneously, at least two ofthe groups R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴,R¹⁵, R¹⁶, R¹⁷, and R¹⁸ are single bonds. The remaining groups can be anycombination of hydrogen atoms, halogen atoms, alkyl groups of C₁ to C₁₀,haloalkyl group of C₁ to C₁₀, aryl groups of C₆ to C₁₀, alkoxy groups ofC₁ to C₁₀, aryloxy groups of C₆ to C₁₀, alkoxycarbonyl groups of C₂ toC₁₀, and aryloxycarbonyl groups of C₇ to C₁₁.

[0073] For the purpose of illustration, the chemical oxidation ofpoly(fluorene) to produce poly(9-fluorenone) is presented in detail.However, the methods described for the chemical oxidation ofpoly(fluorene) to poly(9-fluorenone) are equally applicable to anypolymer containing at least one unit having at least one cyclopentanestructure condensed with at least two aromatic rings, and are allconsidered to be within the scope of the present invention.

[0074] Methods Utilizing Chemical Oxidation of Poly(Fluorene):

[0075] Another embodiment of the present invention is a method for theproduction of poly(9-fluorenone) via chemical oxidation ofpoly(fluorene). The method comprises reacting poly(fluorene), preparedas discussed above, with a chemically prepared oxidizing agent. Thereaction oxidizes one, some or all of the recurring units of fluorene inthe polymer, producing a corresponding polymer of poly(9-fluorenone).

[0076] The reaction temperature is preferably between 0 and 200° C., andmore preferably between room temperature and 180° C. In order to conductthe oxidation smoothly, the molar ratio of oxygen atoms available fromthe oxidizing agent to fluorene units within the polymer is preferably0.5 or more, and more preferably 0.8 to 10. Reaction times are dependenton reactant concentrations, temperatures, etc, but are typically from0.1 to 48 hours and more preferably from 0.2 to 24 hours.

[0077] The resultant poly(9-fluorenone) may contain non-oxidizedfluorene units (as shown in FIG. 5), seen in Example 3, and discussedabove. The amount of fluorene units in the polymer and/or otherimpurities depends on the purity of the starting materials, the reactionconditions of the chemical oxidation, i.e., concentration, nature oramount of chemically prepared oxidizing agent, solvent; the reactiontemperature, reaction time, and others. The poly(9-fluorenone) producedby this method has at least one 9-fluorenone unit and/or at least 1% W/W9-fluorenone units, and preferably has at least 10% W/W 9-fluorenoneunits, more preferably has at least 50% W/W 9-fluorenone units and morepreferably at least 80% 9-fluorenone units.

[0078] Components for Chemical Oxidation of Poly(Fluorene):

[0079] Chemically prepared oxidizing agents of the present invention mayinclude, but are not limited to, bichromic acid and its salts; chromicacid and its salts, chromic oxide (CrO₃); permanganic acid and itssalts; periodic acid and its salts, perbromic acid and its salts,perchloric acid and its salts; percarboxylic acids and their salts suchas peracetic acid and its salts, performic acid and its salts,perpropionic acid and its salts, perbutyric acid and its salts,perbenzoic acid and its salts, m-chloroperbenzoic acid and is salts,perphthalic acid and its salts, trifluoroperacetic acid and its salts;persulfuric acid and its salts; perphosphoric acid and its salts,hydrogen peroxide and its salts; and any mixtures of these compounds. Asthe cationic parts of the salts described above, metals and ammonium canbe used, while alkali metals and alkali earth metals are morepreferable. Among them, alkali metal salts of bichromic acid(bichromates), alkali metal salts of permanganic acid (permanganates),and percarboxylic acids are preferable because of efficiency ofproduction and cost.

[0080] In some preferred embodiments, a solvent can be added to thereaction for the oxidation of the poly(fluorene). As an example of theseembodiments, the oxidizing agent or agents are added to the mixture ofthe poly(9-fluorene) and the solvent and the oxidation reaction thenoccurs. Any solvent may be used for this purpose, as long as it does notprohibit the oxidation reaction. Preferred solvents include: aliphaticcarboxylic acids such as acetic acid, propionic acid, and butyric acid;fluorinated aliphatic carboxylic acids such as trifluoroacetic acid andpentafluoropropionic acid and the like; halogenated hydrocarbons such asmethylene chloride, chloroform, carbon tetrachloride, dichloroethane,trichloroethane, tetrachloroethane, tichlorotrifluoroethane; water; andtheir mixtures. Among them, aliphatic carboxylic acids are morepreferable because of cost of production.

[0081] Having generally described the invention, the same will be morereadily understood by reference to the following examples, which areprovided by way of illustration and are not intended as limiting.

EXAMPLES Example 1

[0082] In a vessel for electrolysis (width 170 mm×depth 60 mm×height 150mm), three nickel plates (each 150 mm×100 mm×0.127 mm) were installed inparallel. The inner nickel plate was a working electrode (anode) and thetwo outer nickel plates were counter electrodes (cathode). 1.2 L of amixture of fluorene (0.01 mol/L) and LiPF₆ (0.1 mol/L) in propylenecarbonate was added to the vessel. The three nickel plates were immersedin the mixture to a depth of 90 mm each. The electrolysis was carriedout by a constant-current method. The electrolysis was carried out for 5hours under the constant-currents of 0.2A, 0.15A, 0.1A, 0.06A, 0.03A andfinally 0.015A with an upper limit of 9V each time. After 5 hours, theinner electrode (anode), on which the polymer was deposited, was pulledout of the electrolyte mixture. The polymer was peeled away from theelectrode and the plate immersed into the electrolyte mixture, and theelectrolysis was repeated 4 times. The collected polymer was washed withpropylene carbonate and then with acetonitrile, and dried at 120° C. for3 hours under vacuum to give 0.89 g of poly(9-fluorenone) as a darkbrown to black solid. The yield was calculated to be 45%poly(9-fluorenone) based on the amount of fluorene used. The spectraldata confirmed that the product was in fact poly(9-fluorenone). The IRspectrum showed a strong absorption band at 1714 cm⁻¹ characteristic ofthe stretching vibration of carbonyl (C═O) of the 9-fluorenonestructure. The physical and spectral data are shown below for ananalytical sample, dried at 170° C. under vacuum for 12 hours:

[0083] Melting points; more than 400° C.

[0084] IR spectrum (KBr, cm⁻); 3040(w), 2921(w), 1714(s) (C═O), 1606(s),1455(s), 1405(m), 1229(m), 816(s), 765(s), 735(m).

[0085] Elemental analysis; Found: C, 83.69%; H, 4.24%; O, 10.22%; F;0.49%; P, 0.51%: total 99.15%. Calcd for C₁₃H₆O: C, 87.63%; H, 3.37%; O,8.98%.

Example 2

[0086] In a vessel for electrolysis (width 170 mm×depth 60 mm×height 150mm), three nickel plates (each 150 mm×100 mm×0.127 mm) were installed inparallel. The inner nickel plate was a working electrode (anode) and thetwo outer nickel plates were counter electrodes (cathode). 1.2 L of amixture of fluorene (0.01 mol/L) and LiPF₆ (0.1 mol/L) in propylenecarbonate was added to the vessel. The three nickel plates were immersedin the mixture to a depth of 90 mm. Two lithium metal sheets (12mm×30mm×0.38 mm) were used as reference electrodes. Each sheet was placedbetween the anode and the cathode. The electrolysis was carried out by apotential-sweep method. The electrolysis was carried out for 4 hoursunder a potential width of 4.5-6.7 V and a sweep time of 50 mV/sec. Theinner electrode (anode) on which the polymer was deposited was pulledout of the electrolyte mixture, and the polymer was peeled off. Theplate was immersed again in the electrolyte mixture. The electrolysiswas repeated two times. The collected polymer was washed with propylenecarbonate and then with acetonitrile, and dried at 120° C. for 5 hoursunder vacuum to give 0.31 g of poly(9-fluorenone) as a dark brown toblack solid. The yield was calculated to be 16% based on the amount offluorene used. The spectral data confirmed that the polymer waspoly(9-fluorenone). The IR spectrum showed a strong absorption band at1714 cm⁻¹ characteristic of the stretching vibration of carbonyl (C═O)of the 9-fluorenone structure. The physical and spectral data are shownbelow for an analytical sample, dried at 170° C. under vacuum for 12hours.

[0087] Melting points; more than 400° C.

[0088] IR spectrum (KBr, cm⁻¹); 3051(w), 2916(w), 1714(s)(C═O), 1606(s),1454(s), 1405(m), 1263(m), 815(s), 767(s), 735(s).

[0089] Elemental analysis; Found: C, 85.94%; H, 4.29%; O, 8%; F; 0.31%;P, 0.21%: total 98.75%. Calcd for C₁₃H₆O: C, 87.63%; H, 3.37%; O, 8.98%.

Example 3

[0090] In a vessel for electrolysis (width 170 mm×depth 60 mm×height 150mm), three nickel plates (each 150 mm×100 mm×0.127 mm) were installed inparallel. The inner nickel plate is a working electrode (anode) and thetwo outer nickel plates are counter electrodes (cathode). 1.2 L of amixture of fluorene (0.05 mol/L) and LiPF₆ (0.2 mol/L) in propylenecarbonate was added to the vessel. The three nickel plates were immersedin the mixture to a depth of 90 mm. The electrolysis was carried out bya constant potential method. The electrolysis was continued for 4 hoursunder the constant potential of 6.6 V, after a constant current of 2 Awas flowed till the potential went up to 6.6V. The inner electrode(anode) was pulled out of the electrolyte mixture, and the polymerpeeled off. The plate was again immersed into the electrolyte mixture.The electrolysis was repeated three times. The collected polymer waswashed with propylene carbonate and then with acetonitrile, and dried at170° C. for 2 hours under vacuum to give 3.83 g of the polymer as a darkbrown to black solid. The yield was calculated to be 38% based on theamount of fluorene used. The IR spectrum showed an absorption band at1716 cm⁻¹ characteristic of the stretching vibration of carbonyl (C═O)of the 9-fluorenone structure. This polymer was determined to be apolymer that contained 9-fluorenone units and fluorene units, calculatedto be about 37:63 ratio of 9-fluorenone units to fluorene units, basedon the oxygen content data of elemental analysis. The physical andspectral data are shown below:

[0091] Melting points; more than 400° C.

[0092] IR spectrum (KBr, cm⁻¹); 3044(w), 3018(w), 2918(w), 2889(w),1716(m)(C═O), 1607(m), 1453(s), 1403(s), 1292(m), 1002(w), 952(w),864(w), 816(s), 766(s), 735(s).

[0093] Elemental analysis; Found: C, 91.42%; H, 4.66%; O, 3.52%; F;0.17%; P, 0.06%: total 99.83%. Calcd for C₁₃H₆O: C, 87.63%; H, 3.37%; O,8.98%.

Example 4

[0094] A 100 mL-vessel contained a platinum plate (25 mm×20 mm) as aworking electrode (anode), a platinum mesh (35 mm×30 mm) as a counterelectrode (cathode), and a reference electrode of Ag/AgNO₃. 25 mL of amixture of fluorene (0.01 mol/L) and (C₂H₅)₄NPF₆ (0.1 mol/L) inpropylene electrolysis carried out for 3 hours at a constant potentialof 2.4V (vs. Ag/AgNO₃). The polymer obtained was dried at 120° C. for 2hours under vacuum to give 7.8 mg of poly(9-fluorenone) as a dark brownto black solid. The physical and spectral data of this polymer agreedwith those of the sample of poly(9-fluorenone), shown in Examples 1 and2.

Examples 5-18

[0095] Examples 5-18 were carried out under the conditions shown inTable 1, and similar to Example 4. The results are also shown inTable 1. In example 18, a lithium electrode was used as a referenceelectrode. Examples 5-8, 10, and 15 were carried out by theconstant-potential method, and Examples 9, 11-14, and 16-18 by thepotential-sweep method. The potential and reaction time are shown forthe constant potential method, and the potential-sweep time per second,the potential-sweep width, and reaction time are shown for thepotential-sweep method. Symbols shown in Table 1 are: PC=propylenecarbonate, Pt=platinum plate, Pt mesh=platinum mesh, Ni=nickel plate,GC=glassy carbon plate, SS=stainless steel plate, Cu=copper plate,A=potential-sweep method, B=constant-potential method, hr=hour. All theproducts obtained were dark brown to black solid and were identified aspolymers having a recurring unit of the 9-fluorenone structure, based onan absorption band of around 1715 cm⁻¹, characteristic of the stretchingvibration of carbonyl (C═O) of the fluorenone structure. TABLE 1 Ex. 5Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10 Ex. 11 Concentration of Fluorene 0.010.005 0.01 0.01 0.01 0.01 0.01 (mol/L) Electrolyte & Concentration LiPF₆0.1 LiPF₆ 0.1 LiPF₆ 0.2 Et₄NBF₄ 0.1 LiPF₆ 0.1 LiPF₆ 0.1 LiPF₆ 0.05(mol/L) Ester & Amount used (mL) PC 100 PC 100 PC 100 PC 25 PC 50 PC 25PC 25 Working Electrode (Anode) Pt 25 × 40 Pt 25 × 40 Pt 25 × 40 Pt NiNi Ni 25 × 20 mm × mm 25 × 20 25 × 25 25 × 20 Counter Electrode Pt mesh40 × 35 Pt mesh 40 × 35 Pt mesh Pt mesh Ni Ni Ni 25 × 20 (Cathode) mm ×mm 40 × 35 35 × 30 25 × 25 25 × 20 Electrolysis Conditions B 1.6V 4 hr B1.6V 4 hr B 1.6V B A B A 20 mV/s 4hr 2.4V 3 hr 50 mV/s 0.5- 2.7V1.7-2.7V 6 hr 2.7V 12.3 hr 3 hr Yield of Polymer (mg) 10.8 9.6 12.1 3.717.5 5.6 5.6 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18Concentration of Fluorene 0.1 0.01 0.01 0.01 0.01 0.01 0.01 (mol/L)Electrolyte & Concentration LiPF₆ 0.5 LiPF₆ 0.1 LiPF₆ 0.1 LiPF₆ 0.05LiPF₆ 0.1 LiPF₆ 0.1 LiPF₆ 0.1 (mol/L) Ester & Amount used (mL) PC 25 PC50 PC 10 PC 50 PC 50 PC 50 PC 50 Working Electrode (Anode) Ni 25 × 20 GCGC 10 × 20 GC 25 × 25 GC SS 30 × 30 Ni mm × mm 25 × 25 25 × 25 25 × 30Counter Electrode (Cathode) Ni 25 × 20 Ni 25 × 25 GC 10 × 20 GC 25 × 25Cu SS 30 × 30 Ni mm × mm 25 × 25 25 × 30 Electrolysis Conditions A 20mV/s A 50 mV/s A 50 mV/s B 2.5V A A 50 mV/s A 1.7-2.7V 6 hr 0.5-2.7V0.5-2.6V 12.8 hr 4 hr 50 mV/s 0.5- 0.5-2.7V 12.3 hr 50 mV/s 4.0- 12.3 hr2.7V 12.3 hr 6.8V 15.8 hr Yield of Polymer (mg) 48.8 36.3 7.3 7.7 25.216.9 17.7

Example 19 Electrolysis of Fluorene in a Simple Ester

[0096] A vessel in which a platinum plate (25 mm×35 mm) as a workingelectrode (anode), a platinum mesh (40 mm×30 mm) as a counter electrode(cathode), and a reference electrode of Ag/AgNO₃ are set, 100 mL of amixture of fluorene (0.01 mol/L) and of LiPF₆ (0.1 mol/L) in ethylacetate was added. After the electrolysis vessel was purged with argongas, and the electrolysis carried out for 12 hours at the constantpotential of 1.35V (vs. Ag/AgNO₃). Total amount of electric current was5.59 mA/h. The polymer was deposited on the working electrode, peeledoff, and dried at 170° C. for 2 hours under vacuum (1 mmHg) to give 0.4mg of poly(9-fluorenone) as a dark brown to black solid. The IR spectraldata of this polymer agreed with those of poly(9-fluorenone) obtained bythe electrolysis in propylene carbonate.

Example 20 Electrolytic Oxidation of Poly(Fluorene)

[0097] According to the literature, poly(fluorene) was prepared by theelectrolytic polymerization of fluorene in acetonitrile containing LiPF₆(0.1 mol/L) in an electrolytic cell installed with a platinum plate (40mm×25 mm) as a working electrode (anode), a platinum mesh (40 mm×35 mm)as a counter electrode (cathode), and a reference Ag/AgNO₃ electrode.The conditions of the polymerization were a constant potential of 1.35 Vand a total current amount flowed of 2.60 mAh. The platinum plate inwhich the back side of the plate was coated with a poly(vinylidenefluoride) film was used for the electrolytic polymerization. Theresulting poly(fluorene) was deposited on the front side of the platinumplate.

[0098] The platinum plate having poly(fluorene) was then set in anotherelectrolytic cell having a platinum mesh (40 mm×35 mm), a referenceAg/AgNO₃ electrode, and propylene carbonate containing LiPF₆ (0.1mol/L). The poly(fluorene) was electrolytically oxidized in theelectrolytic cell; the electric current amount flowed between theelectrodes at 2.7 V was 5.0 mAh. The resulting product was peeled fromthe platinum plate, resulting in 5.0 mg of poly(fluorenone) as a darkbrown to black solid. In the IR spectrum, there was observed a strongabsorption band at 1716 cm⁻¹ characteristic of the stretching vibrationof carbonyl (C═O) of the fluorenone structure.

[0099] IR spectrum (KBr, cm⁻¹); 3042(w), 2977(w), 2924(w), 1716(s)(C═O),1608(s), 1453(m), 1232(s), 818(s), 787(w), 766(w).

Example 21 Chemical Oxidation of Poly(Fluorene)

[0100] To a mixture of 164 mg (1 mmol/fluorene unit) of poly(fluorene)and 4 mL of acetic acid, was added 983 mg (3.3 mmol) of sodiumbichromate dihydrate. The reaction mixture was refluxed for 5 hours, andthe reaction mixture poured into ice water. The solid was filtered,washed with water and methanol, and dried at 170° C. for 1 hour to give149 mg (84%) of poly(9-fluorenone). The product was confirmed aspoly(9-fluorenone) by spectral analysis; in the IR spectrum, a strongabsorption band at 1715 cm⁻¹ characteristic of the stretching vibrationof carbonyl (C═O) of the 9-fluorenone structure was observed, while theabsorption bands around 2920 cm⁻¹ corresponding to the 9-methylene (CH₂)of the fluorene structure essentially disappeared.

[0101] IR spectrum (KBr, cm⁻¹); 3048(w), 1715(s)(C═O), 1604(s), 1452(s),1234(m), 1187(m), 1114(s), 831(m), 787(w), 764(m), 740(m), 678(w),669(w), 653(w).

[0102] The poly(fluorene) used in this Example was prepared byelectrolytic polymerization of fluorene (0.01 mol/L) in acetonitrileusing LiPF₆ (0.1 mol/L) as an electrolyte according to the literature.Journal of Electrochemical Society, Vol. 132, p.p. 631-634 (1985).

[0103] It will be clear that the present invention is well adapted toattain the ends and advantages mentioned as well as those inherenttherein. While a presently preferred embodiment has been described forpurposes of this disclosure, various changes and modifications may bemade which are well within the scope of the present invention. Numerousother changes may be made which will readily suggest themselves to thoseskilled in the art and which are encompassed in the spirit of theinvention disclosed and as defined in the appended claims.

[0104] The entire disclosure and all publications cited herein arehereby incorporated by reference.

What is claimed is:
 1. A method for the production of a polymer havingat least one unit that contains at least one cyclopentanone structurecondensed with at least two aromatic rings, the method comprising:passing an electric current between two or more electrodes immersed inan electrolytic mixture comprising an ester and an electrolyte, whereinone or more of the electrodes includes an aromatic compound polymerhaving at least one unit of a at least one cyclopentane structurecondensed with at least two aromatic rings.
 2. The method of claim 1wherein the electrolyte in the electrolytic mixture comprises anelectrolyte selected from the group consisting essentially of LiPF₆,NaPF₆, KPF₆, LiBF₄, NaBF₄, KBF₄, (CH₃)₄NPF₆, (CH₃)₄NBF₄, (C₂H_(s))₄NPF₆,(C₂H_(s))₄NBF₄, and mixtures thereof.
 3. The method of claim 1 whereinthe mixture further comprises a solvent.
 4. The method of claim 1wherein the ester is selected from the group consisting of a simpleester, a carbonic ester, a lactone, a complex ester, and mixturesthereof.
 5. The method of claim 1 wherein the ester is a simple esterselected from the group consisting of methyl formate, ethyl formate,methyl acetate, ethyl acetate, methyl propionate, ethyl propionate,methyl butyrate, and mixtures thereof.
 6. The method of claim 1 whereinthe ester is a lactone selected from the group consisting ofβ-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, andmixtures thereof.
 7. The method of claim 1 wherein the ester is acarbonic ester selected from the group consisting of ethylene carbonate,propylene carbonate, butylene carbonate, dimethyl carbonate, diethylcarbonate, ethyl methyl carbonate, and mixtures thereof.
 8. The methodof claim 1 wherein the concentration of ester in the mixture is greaterthan 20% by volume.
 9. The method of claim 1 further comprising one ormore electrodes used as reference electrodes for voltage control. 10.The method of claim 1 wherein the electrodes are comprised of one ormore of platinum, nickel, stainless steel, copper, carbon, PbO₂, andtitanium coated with platinum or PbO₂.
 11. The method of claim 1 whereinthe aromatic compound polymer having at least one unit of at least onecyclopentane structure condensed with at least two aromatic rings isdeposited on the one or more electrodes.
 12. The method of claim 1wherein the aromatic compound polymer having at least one unit of atleast one cyclopentane structure condensed with at least two aromaticrings is comprised of at least 10% by weight units that contain at leastone cyclopentane structure condensed with at least two aromatic rings.13. The method of claim 1 wherein the aromatic compound polymer havingat least one unit of at least one cyclopentane structure condensed withat least two aromatic rings is comprised of at least 50% by weight unitsthat contain at least one cyclopentane structure condensed with at leasttwo aromatic rings.
 14. The method of claim 1 wherein the concentrationof electrolyte is in the range 0.001-1 mol/L.
 15. The method of claim 1further comprising one or more electrodes used as reference electrodesfor voltage control.
 16. The method of claim 1 wherein the polymerhaving at least one unit that contains at least one cyclopentanonestructure condensed with at least two aromatic rings ispoly(9-fluorenone) and the aromatic compound polymer having at least oneunit of at least one cyclopentane structure condensed with at least twoaromatic rings is poly(fluorene).
 17. The method of claim 1 wherein thepolymer having at least one unit that contains at least onecyclopentanone structure condensed with at least two aromatic rings ispoly(cyclopenta[def]phenanthren-4-one) and the aromatic compound polymerhaving at least one unit of at least one cyclopentane structurecondensed with at least two aromatic rings ispoly(4H-cyclopenta[def]phenanthrene).
 18. The method of claim 1 whereinthe polymer having at least one unit that contains at least onecyclopentanone structure condensed with at least two aromatic rings ispoly(8H-cyclopenta[def]fluoren-4-one) and the aromatic compound polymerhaving at least one unit of at least one cyclopentane structurecondensed with at least two aromatic rings ispoly(4,8-dihydro-cyclopenta[def]fluorene).
 19. The method of claim 1wherein the polymer having at least one unit that contains at least onecyclopentanone structure condensed with at least two aromatic rings ispoly(cyclopenta[def]fluorene-4,8-dione) and the aromatic compoundpolymer having at least one unit of at least one cyclopentane structurecondensed with at least two aromatic rings ispoly(4,8-dihydro-cyclopenta[def]fluorene).
 20. The method of claim 1wherein the polymer having at least one unit that contains at least onecyclopentanone structure condensed with at least two aromatic rings ispoly(benzo[b]fluoren-11-one) and the aromatic compound polymer having atleast one unit of at least one cyclopentane structure condensed with atleast two aromatic rings is poly(11H-benzo[b]fluorene).
 21. The methodof claim 1 wherein the polymer having at least one unit that contains atleast one cyclopentanone structure condensed with at least two aromaticrings is poly(dibenzo[b,h]fluoren-12-one) and the aromatic compoundpolymer having at least one unit of at least one cyclopentane structurecondensed with at least two aromatic rings is poly(12H-dibenzo[b,h]fluorene).
 22. The method of claim 1 wherein the polymer having atleast one unit that contains at least one cyclopentanone structurecondensed with at least two aromatic rings ispoly(indeno[1,2-b]fluorene-6,12-dione) and the aromatic compound polymerhaving at least one unit of at least one unit of at least onecyclopentane structure condensed with at least two aromatic rings ispoly(6,12-dihydro-indeno[1,2-b]fluorine).